Is zero tds possible with RO only?

[lastlight]

I'm in Calgary btw. My dual stage meter shows the source water to be about 280 (though I just dipped the inline probe in a glass of water to avoid making more cuts in my pipes to make sure the meter showd anything other than 0). I'm getting a reading of 0 without running DI. The unit has 5 micron sediment, 5 micron MATRIKX CTO/2 carbon and then dow filmtec 75 gpd membrane.

With 98% rejection rate I was expecting around 280 x 0.02 = 6 or so

When I first set things up btw I was getting a reading of 1 after the RO but after 10 min or so it read 0.